package org.sandroproxy.web;

import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.URLEncoder;
import java.util.Date;
import java.util.Enumeration;
import java.util.Vector;
import java.util.Hashtable;
import java.util.Locale;
import java.util.Properties;
import java.util.StringTokenizer;
import java.util.TimeZone;
import java.util.logging.Level;
import java.util.logging.Logger;

import java.io.ByteArrayOutputStream;
import java.io.FileOutputStream;

/**
 * A simple, tiny, nicely embeddable HTTP 1.0 (partially 1.1) server in Java
 *
 * <p> NanoHTTPD version 1.25,
 * Copyright &copy; 2001,2005-2012 Jarno Elonen (elonen@iki.fi, http://iki.fi/elonen/)
 * and Copyright &copy; 2010 Konstantinos Togias (info@ktogias.gr, http://ktogias.gr)
 *
 * <p><b>Features + limitations: </b><ul>
 *
 *    <li> Only one Java file </li>
 *    <li> Java 1.1 compatible </li>
 *    <li> Released as open source, Modified BSD licence </li>
 *    <li> No fixed config files, logging, authorization etc. (Implement yourself if you need them.) </li>
 *    <li> Supports parameter parsing of GET and POST methods (+ rudimentary PUT support in 1.25) </li>
 *    <li> Supports both dynamic content and file serving </li>
 *    <li> Supports file upload (since version 1.2, 2010) </li>
 *    <li> Supports partial content (streaming)</li>
 *    <li> Supports ETags</li>
 *    <li> Never caches anything </li>
 *    <li> Doesn't limit bandwidth, request time or simultaneous connections </li>
 *    <li> Default code serves files and shows all HTTP parameters and headers</li>
 *    <li> File server supports directory listing, index.html and index.htm</li>
 *    <li> File server supports partial content (streaming)</li>
 *    <li> File server supports ETags</li>
 *    <li> File server does the 301 redirection trick for directories without '/'</li>
 *    <li> File server supports simple skipping for files (continue download) </li>
 *    <li> File server serves also very long files without memory overhead </li>
 *    <li> Contains a built-in list of most common mime types </li>
 *    <li> All header names are converted lowercase so they don't vary between browsers/clients </li>
 *
 * </ul>
 *
 * <p><b>Ways to use: </b><ul>
 *
 *    <li> Run as a standalone app, serves files and shows requests</li>
 *    <li> Subclass serve() and embed to your own program </li>
 *    <li> Call serveFile() from serve() with your own base directory </li>
 *
 * </ul>
 *
 * See the end of the source file for distribution license
 * (Modified BSD licence)
 */
public class NanoHTTPD
{
    // ==================================================
    // API parts
    // ==================================================

    /**
     * Override this to customize the server.<p>
     *
     * (By default, this delegates to serveFile() and allows directory listing.)
     *
     * @param uri   Percent-decoded URI without parameters, for example "/index.cgi"
     * @param method    "GET", "POST" etc.
     * @param parms Parsed, percent decoded parameters from URI and, in case of POST, data.
     * @param header    Header entries, percent decoded
     * @return HTTP response, see class Response for details
     */
    public Response serve( String uri, String method, Properties header, Properties parms, Properties files )
    {
        _logger.finer(TAG + method + " '" + uri + "' " );
        
        Enumeration e = header.propertyNames();
        while ( e.hasMoreElements())
        {
            String value = (String)e.nextElement();
            _logger.finer( TAG + "  HDR: '" + value + "' = '" +
                                header.getProperty( value ) + "'" );
        }
        e = parms.propertyNames();
        while ( e.hasMoreElements())
        {
            String value = (String)e.nextElement();
            _logger.finer( TAG + "  PRM: '" + value + "' = '" +
                                parms.getProperty( value ) + "'" );
        }
        e = files.propertyNames();
        while ( e.hasMoreElements())
        {
            String value = (String)e.nextElement();
            _logger.finer( TAG + "  UPLOADED: '" + value + "' = '" +
                                files.getProperty( value ) + "'" );
        }

        return serveFile( uri, header, myRootDir, true );
    }

    /**
     * HTTP response.
     * Return one of these from serve().
     */
    public class Response
    {
        /**
         * Default constructor: response = HTTP_OK, data = mime = 'null'
         */
        public Response()
        {
            this.status = HTTP_OK;
        }

        /**
         * Basic constructor.
         */
        public Response( String status, String mimeType, InputStream data )
        {
            this.status = status;
            this.mimeType = mimeType;
            this.data = data;
        }

        /**
         * Convenience method that makes an InputStream out of
         * given text.
         */
        public Response( String status, String mimeType, String txt )
        {
            this.status = status;
            this.mimeType = mimeType;
            try
            {
                this.data = new ByteArrayInputStream( txt.getBytes("UTF-8"));
            }
            catch ( java.io.UnsupportedEncodingException uee )
            {
                uee.printStackTrace();
            }
        }

        /**
         * Adds given line to the header.
         */
        public void addHeader( String name, String value )
        {
            header.put( name, value );
        }

        /**
         * HTTP status code after processing, e.g. "200 OK", HTTP_OK
         */
        public String status;

        /**
         * MIME type of content, e.g. "text/html"
         */
        public String mimeType;

        /**
         * Data of the response, may be null.
         */
        public InputStream data;

        /**
         * Headers for the HTTP response. Use addHeader()
         * to add lines.
         */
        public Properties header = new Properties();
    }

    /**
     * Some HTTP response status codes
     */
    public static final String
        HTTP_OK = "200 OK",
        HTTP_PARTIALCONTENT = "206 Partial Content",
        HTTP_RANGE_NOT_SATISFIABLE = "416 Requested Range Not Satisfiable",
        HTTP_REDIRECT = "301 Moved Permanently",
        HTTP_NOTMODIFIED = "304 Not Modified",
        HTTP_FORBIDDEN = "403 Forbidden",
        HTTP_NOTFOUND = "404 Not Found",
        HTTP_BADREQUEST = "400 Bad Request",
        HTTP_INTERNALERROR = "500 Internal Server Error",
        HTTP_NOTIMPLEMENTED = "501 Not Implemented";

    /**
     * Common mime types for dynamic content
     */
    public static final String
        MIME_PLAINTEXT = "text/plain; charset=UTF-8",
        MIME_HTML = "text/html; charset=UTF-8",
        MIME_DEFAULT_BINARY = "application/octet-stream",
        MIME_JSON = "application/json; charset=UTF-8",
        MIME_XML = "text/xml; charset=UTF-8";

    // ==================================================
    // Socket & server code
    // ==================================================

    /**
     * Starts a HTTP server to given port.<p>
     * Throws an IOException if the socket is already in use
     */
    public NanoHTTPD( int port, File wwwroot ) throws IOException
    {
        myTcpPort = port;
        this.myRootDir = wwwroot;
        myServerSocket = new ServerSocket( myTcpPort );
        _logger.setLevel(Level.FINEST);
    }
    
    public void startServer() throws IOException {
        myThread = new Thread( new Runnable()
            {
                public void run()
                {
                    try
                    {
                        while( true )
                            new HTTPSession( myServerSocket.accept());
                    }
                    catch ( IOException ioe )
                    {}
                }
            });
        myThread.setDaemon( true );
        myThread.start();
    }

    /**
     * Stops the server.
     */
    public void stop()
    {
        try
        {
            myServerSocket.close();
            myThread.join();
        }
        catch ( IOException ioe ) {}
        catch ( InterruptedException e ) {}
    }


    /**
     * Starts as a standalone file server and waits for Enter.
     */
    public static void main( String[] args )
    {
        _logger.finer( "NanoHTTPD 1.25 (C) 2001,2005-2011 Jarno Elonen and (C) 2010 Konstantinos Togias\n" +
                "(Command line options: [-p port] [-d root-dir] [--licence])\n" );

        // Defaults
        int port = 80;
        File wwwroot = new File(".").getAbsoluteFile();

        // Show licence if requested
        for ( int i=0; i<args.length; ++i )
        if(args[i].equalsIgnoreCase("-p"))
            port = Integer.parseInt( args[i+1] );
        else if(args[i].equalsIgnoreCase("-d"))
            wwwroot = new File( args[i+1] ).getAbsoluteFile();
        else if ( args[i].toLowerCase().endsWith( "licence" ))
        {
            _logger.finer( LICENCE + "\n" );
            break;
        }

        try
        {
            new NanoHTTPD( port, wwwroot );
        }
        catch( IOException ioe )
        {
            _logger.finer( "Couldn't start server:\n" + ioe );
            System.exit( -1 );
        }

        _logger.finer( "Now serving files in port " + port + " from \"" + wwwroot + "\"" );
        _logger.finer( "Hit Enter to stop.\n" );

        try { System.in.read(); } catch( Throwable t ) {}
    }

    /**
     * Handles one session, i.e. parses the HTTP request
     * and returns the response.
     */
    private class HTTPSession implements Runnable
    {
        public HTTPSession( Socket s )
        {
            mySocket = s;
            Thread t = new Thread( this );
            t.setDaemon( true );
            t.start();
        }

        public void run()
        {
            try
            {
                InputStream is = mySocket.getInputStream();
                if ( is == null) return;

                // Read the first 8192 bytes.
                // The full header should fit in here.
                // Apache's default header limit is 8KB.
                int bufsize = 8192;
                byte[] buf = new byte[bufsize];
                int rlen = is.read(buf, 0, bufsize);
                if (rlen <= 0) return;

                // Create a BufferedReader for parsing the header.
                ByteArrayInputStream hbis = new ByteArrayInputStream(buf, 0, rlen);
                BufferedReader hin = new BufferedReader( new InputStreamReader( hbis ));
                Properties pre = new Properties();
                Properties parms = new Properties();
                Properties header = new Properties();
                Properties files = new Properties();

                // Decode the header into parms and header java properties
                decodeHeader(hin, pre, parms, header);
                String method = pre.getProperty("method");
                String uri = pre.getProperty("uri");

                long size = 0x7FFFFFFFFFFFFFFFl;
                String contentLength = header.getProperty("content-length");
                if (contentLength != null)
                {
                    try { size = Integer.parseInt(contentLength); }
                    catch (NumberFormatException ex) {}
                }

                // We are looking for the byte separating header from body.
                // It must be the last byte of the first two sequential new lines.
                int splitbyte = 0;
                boolean sbfound = false;
                while (splitbyte < rlen)
                {
                    if (buf[splitbyte] == '\r' && buf[++splitbyte] == '\n' && buf[++splitbyte] == '\r' && buf[++splitbyte] == '\n') {
                        sbfound = true;
                        break;
                    }
                    splitbyte++;
                }
                splitbyte++;

                // Write the part of body already read to ByteArrayOutputStream f
                ByteArrayOutputStream f = new ByteArrayOutputStream();
                if (splitbyte < rlen) f.write(buf, splitbyte, rlen-splitbyte);

                // While Firefox sends on the first read all the data fitting
                // our buffer, Chrome and Opera sends only the headers even if
                // there is data for the body. So we do some magic here to find
                // out whether we have already consumed part of body, if we
                // have reached the end of the data to be sent or we should
                // expect the first byte of the body at the next read.
                if (splitbyte < rlen)
                    size -= rlen - splitbyte +1;
                else if (!sbfound || size == 0x7FFFFFFFFFFFFFFFl)
                    size = 0;

                // Now read all the body and write it to f
                buf = new byte[512];
                while ( rlen >= 0 && size > 0 )
                {
                    rlen = is.read(buf, 0, 512);
                    size -= rlen;
                    if (rlen > 0)
                        f.write(buf, 0, rlen);
                }

                // Get the raw body as a byte []
                byte [] fbuf = f.toByteArray();

                // Create a BufferedReader for easily reading it as string.
                ByteArrayInputStream bin = new ByteArrayInputStream(fbuf);
                BufferedReader in = new BufferedReader( new InputStreamReader(bin));

                // If the method is POST, there may be parameters
                // in data section, too, read it:
                if ( method.equalsIgnoreCase( "POST" ))
                {
                    String contentType = "";
                    String contentTypeHeader = header.getProperty("content-type");
                    StringTokenizer st = new StringTokenizer( contentTypeHeader , "; " );
                    if ( st.hasMoreTokens()) {
                        contentType = st.nextToken();
                    }

                    if (contentType.equalsIgnoreCase("multipart/form-data"))
                    {
                        // Handle multipart/form-data
                        if ( !st.hasMoreTokens())
                            sendError( HTTP_BADREQUEST, "BAD REQUEST: Content type is multipart/form-data but boundary missing. Usage: GET /example/file.html" );
                        String boundaryExp = st.nextToken();
                        st = new StringTokenizer( boundaryExp , "=" );
                        if (st.countTokens() != 2)
                            sendError( HTTP_BADREQUEST, "BAD REQUEST: Content type is multipart/form-data but boundary syntax error. Usage: GET /example/file.html" );
                        st.nextToken();
                        String boundary = st.nextToken();

                        decodeMultipartData(boundary, fbuf, in, parms, files);
                    }
                    else
                    {
                        // Handle application/x-www-form-urlencoded
                        String postLine = "";
                        char pbuf[] = new char[512];
                        int read = in.read(pbuf);
                        while ( read >= 0 && !postLine.endsWith("\r\n") )
                        {
                            postLine += String.valueOf(pbuf, 0, read);
                            read = in.read(pbuf);
                        }
                        postLine = postLine.trim();
                        decodeParms( postLine, parms );
                    }
                }

                if ( method.equalsIgnoreCase( "PUT" ))
                    files.put("content", saveTmpFile( fbuf, 0, f.size()));

                // Ok, now do the serve()
                Response r = serve( uri, method, header, parms, files );
                if ( r == null )
                    sendError( HTTP_INTERNALERROR, "SERVER INTERNAL ERROR: Serve() returned a null response." );
                else
                    sendResponse( r.status, r.mimeType, r.header, r.data );

                in.close();
                is.close();
            }
            catch ( IOException ioe )
            {
                try
                {
                    sendError( HTTP_INTERNALERROR, "SERVER INTERNAL ERROR: IOException: " + ioe.getMessage());
                }
                catch ( Throwable t ) {}
            }
            catch ( InterruptedException ie )
            {
                // Thrown by sendError, ignore and exit the thread.
            }
        }

        /**
         * Decodes the sent headers and loads the data into
         * java Properties' key - value pairs
        **/
        private  void decodeHeader(BufferedReader in, Properties pre, Properties parms, Properties header)
            throws InterruptedException
        {
            try {
                // Read the request line
                String inLine = in.readLine();
                if (inLine == null) return;
                StringTokenizer st = new StringTokenizer( inLine );
                if ( !st.hasMoreTokens())
                    sendError( HTTP_BADREQUEST, "BAD REQUEST: Syntax error. Usage: GET /example/file.html" );

                String method = st.nextToken();
                pre.put("method", method);

                if ( !st.hasMoreTokens())
                    sendError( HTTP_BADREQUEST, "BAD REQUEST: Missing URI. Usage: GET /example/file.html" );

                String uri = st.nextToken();

                // Decode parameters from the URI
                int qmi = uri.indexOf( '?' );
                if ( qmi >= 0 )
                {
                    decodeParms( uri.substring( qmi+1 ), parms );
                    uri = decodePercent( uri.substring( 0, qmi ));
                }
                else uri = decodePercent(uri);

                // If there's another token, it's protocol version,
                // followed by HTTP headers. Ignore version but parse headers.
                // NOTE: this now forces header names lowercase since they are
                // case insensitive and vary by client.
                if ( st.hasMoreTokens())
                {
                    String line = in.readLine();
                    while ( line != null && line.trim().length() > 0 )
                    {
                        int p = line.indexOf( ':' );
                        if ( p >= 0 )
                            header.put( line.substring(0,p).trim().toLowerCase(), line.substring(p+1).trim());
                        line = in.readLine();
                    }
                }

                pre.put("uri", uri);
            }
            catch ( IOException ioe )
            {
                sendError( HTTP_INTERNALERROR, "SERVER INTERNAL ERROR: IOException: " + ioe.getMessage());
            }
        }

        /**
         * Decodes the Multipart Body data and put it
         * into java Properties' key - value pairs.
        **/
        private void decodeMultipartData(String boundary, byte[] fbuf, BufferedReader in, Properties parms, Properties files)
            throws InterruptedException
        {
            try
            {
                int[] bpositions = getBoundaryPositions(fbuf,boundary.getBytes());
                int boundarycount = 1;
                String mpline = in.readLine();
                while ( mpline != null )
                {
                    if (mpline.indexOf(boundary) == -1)
                        sendError( HTTP_BADREQUEST, "BAD REQUEST: Content type is multipart/form-data but next chunk does not start with boundary. Usage: GET /example/file.html" );
                    boundarycount++;
                    Properties item = new Properties();
                    mpline = in.readLine();
                    while (mpline != null && mpline.trim().length() > 0)
                    {
                        int p = mpline.indexOf( ':' );
                        if (p != -1)
                            item.put( mpline.substring(0,p).trim().toLowerCase(), mpline.substring(p+1).trim());
                        mpline = in.readLine();
                    }
                    if (mpline != null)
                    {
                        String contentDisposition = item.getProperty("content-disposition");
                        if (contentDisposition == null)
                        {
                            sendError( HTTP_BADREQUEST, "BAD REQUEST: Content type is multipart/form-data but no content-disposition info found. Usage: GET /example/file.html" );
                        }
                        StringTokenizer st = new StringTokenizer( contentDisposition , "; " );
                        Properties disposition = new Properties();
                        while ( st.hasMoreTokens())
                        {
                            String token = st.nextToken();
                            int p = token.indexOf( '=' );
                            if (p!=-1)
                                disposition.put( token.substring(0,p).trim().toLowerCase(), token.substring(p+1).trim());
                        }
                        String pname = disposition.getProperty("name");
                        pname = pname.substring(1,pname.length()-1);

                        String value = "";
                        if (item.getProperty("content-type") == null) {
                            while (mpline != null && mpline.indexOf(boundary) == -1)
                            {
                                mpline = in.readLine();
                                if ( mpline != null)
                                {
                                    int d = mpline.indexOf(boundary);
                                    if (d == -1)
                                        value+=mpline;
                                    else
                                        value+=mpline.substring(0,d-2);
                                }
                            }
                        }
                        else
                        {
                            if (boundarycount> bpositions.length)
                                sendError( HTTP_INTERNALERROR, "Error processing request" );
                            int offset = stripMultipartHeaders(fbuf, bpositions[boundarycount-2]);
                            String path = saveTmpFile(fbuf, offset, bpositions[boundarycount-1]-offset-4);
                            files.put(pname, path);
                            value = disposition.getProperty("filename");
                            value = value.substring(1,value.length()-1);
                            do {
                                mpline = in.readLine();
                            } while (mpline != null && mpline.indexOf(boundary) == -1);
                        }
                        parms.put(pname, value);
                    }
                }
            }
            catch ( IOException ioe )
            {
                sendError( HTTP_INTERNALERROR, "SERVER INTERNAL ERROR: IOException: " + ioe.getMessage());
            }
        }

        /**
         * Find the byte positions where multipart boundaries start.
        **/
        public int[] getBoundaryPositions(byte[] b, byte[] boundary)
        {
            int matchcount = 0;
            int matchbyte = -1;
            Vector matchbytes = new Vector();
            for (int i=0; i<b.length; i++)
            {
                if (b[i] == boundary[matchcount])
                {
                    if (matchcount == 0)
                        matchbyte = i;
                    matchcount++;
                    if (matchcount==boundary.length)
                    {
                        matchbytes.addElement(new Integer(matchbyte));
                        matchcount = 0;
                        matchbyte = -1;
                    }
                }
                else
                {
                    i -= matchcount;
                    matchcount = 0;
                    matchbyte = -1;
                }
            }
            int[] ret = new int[matchbytes.size()];
            for (int i=0; i < ret.length; i++)
            {
                ret[i] = ((Integer)matchbytes.elementAt(i)).intValue();
            }
            return ret;
        }

        /**
         * Retrieves the content of a sent file and saves it
         * to a temporary file.
         * The full path to the saved file is returned.
        **/
        private String saveTmpFile(byte[] b, int offset, int len)
        {
            String path = "";
            if (len > 0)
            {
                String tmpdir = System.getProperty("java.io.tmpdir");
                try {
                    File temp = File.createTempFile("NanoHTTPD", "", new File(tmpdir));
                    OutputStream fstream = new FileOutputStream(temp);
                    fstream.write(b, offset, len);
                    fstream.close();
                    path = temp.getAbsolutePath();
                } catch (Exception e) { // Catch exception if any
                    _logger.finer(TAG + "Error: " + e.getMessage());
                }
            }
            return path;
        }


        /**
         * It returns the offset separating multipart file headers
         * from the file's data.
        **/
        private int stripMultipartHeaders(byte[] b, int offset)
        {
            int i = 0;
            for (i=offset; i<b.length; i++)
            {
                if (b[i] == '\r' && b[++i] == '\n' && b[++i] == '\r' && b[++i] == '\n')
                    break;
            }
            return i+1;
        }

        /**
         * Decodes the percent encoding scheme. <br/>
         * For example: "an+example%20string" -> "an example string"
         */
        private String decodePercent( String str ) throws InterruptedException
        {
            try
            {
                StringBuffer sb = new StringBuffer();
                for( int i=0; i<str.length(); i++ )
                {
                    char c = str.charAt( i );
                    switch ( c )
                    {
                        case '+':
                            sb.append( ' ' );
                            break;
                        case '%':
                            sb.append((char)Integer.parseInt( str.substring(i+1,i+3), 16 ));
                            i += 2;
                            break;
                        default:
                            sb.append( c );
                            break;
                    }
                }
                return sb.toString();
            }
            catch( Exception e )
            {
                sendError( HTTP_BADREQUEST, "BAD REQUEST: Bad percent-encoding." );
                return null;
            }
        }

        /**
         * Decodes parameters in percent-encoded URI-format
         * ( e.g. "name=Jack%20Daniels&pass=Single%20Malt" ) and
         * adds them to given Properties. NOTE: this doesn't support multiple
         * identical keys due to the simplicity of Properties -- if you need multiples,
         * you might want to replace the Properties with a Hashtable of Vectors or such.
         */
        private void decodeParms( String parms, Properties p )
            throws InterruptedException
        {
            if ( parms == null )
                return;

            StringTokenizer st = new StringTokenizer( parms, "&" );
            while ( st.hasMoreTokens())
            {
                String e = st.nextToken();
                int sep = e.indexOf( '=' );
                if ( sep >= 0 )
                    p.put( decodePercent( e.substring( 0, sep )).trim(),
                           decodePercent( e.substring( sep+1 )));
            }
        }

        /**
         * Returns an error message as a HTTP response and
         * throws InterruptedException to stop further request processing.
         */
        private void sendError( String status, String msg ) throws InterruptedException
        {
            sendResponse( status, MIME_PLAINTEXT, null, new ByteArrayInputStream( msg.getBytes()));
            throw new InterruptedException();
        }

        /**
         * Sends given response to the socket.
         */
        private void sendResponse( String status, String mime, Properties header, InputStream data )
        {
            try
            {
                if ( status == null )
                    throw new Error( "sendResponse(): Status can't be null." );

                OutputStream out = mySocket.getOutputStream();
                PrintWriter pw = new PrintWriter( out );
                pw.print("HTTP/1.0 " + status + " \r\n");

                if ( mime != null )
                    pw.print("Content-Type: " + mime + "\r\n");

                if ( header == null || header.getProperty( "Date" ) == null )
                    pw.print( "Date: " + gmtFrmt.format( new Date()) + "\r\n");

                if ( header != null )
                {
                    Enumeration e = header.keys();
                    while ( e.hasMoreElements())
                    {
                        String key = (String)e.nextElement();
                        String value = header.getProperty( key );
                        pw.print( key + ": " + value + "\r\n");
                    }
                }

                pw.print("\r\n");
                pw.flush();

                if ( data != null )
                {
                    int pending = data.available(); // This is to support partial sends, see serveFile()
                    byte[] buff = new byte[theBufferSize];
                    while (pending>0)
                    {
                        int read = data.read( buff, 0, ( (pending>theBufferSize) ?  theBufferSize : pending ));
                        if (read <= 0)  break;
                        out.write( buff, 0, read );
                        pending -= read;
                    }
                }
                out.flush();
                out.close();
                if ( data != null )
                    data.close();
            }
            catch( IOException ioe )
            {
                // Couldn't write? No can do.
                try { mySocket.close(); } catch( Throwable t ) {}
            }
        }

        private Socket mySocket;
    }

    /**
     * URL-encodes everything between "/"-characters.
     * Encodes spaces as '%20' instead of '+'.
     */
    private String encodeUri( String uri )
    {
        String newUri = "";
        StringTokenizer st = new StringTokenizer( uri, "/ ", true );
        while ( st.hasMoreTokens())
        {
            String tok = st.nextToken();
            if ( tok.equals( "/" ))
                newUri += "/";
            else if ( tok.equals( " " ))
                newUri += "%20";
            else
            {
                newUri += URLEncoder.encode( tok );
                // For Java 1.4 you'll want to use this instead:
                // try { newUri += URLEncoder.encode( tok, "UTF-8" ); } catch ( java.io.UnsupportedEncodingException uee ) {}
            }
        }
        return newUri;
    }

    private int myTcpPort;
    private final ServerSocket myServerSocket;
    private Thread myThread;
    private File myRootDir;

    // ==================================================
    // File server code
    // ==================================================

    /**
     * Serves file from homeDir and its' subdirectories (only).
     * Uses only URI, ignores all headers and HTTP parameters.
     */
    public Response serveFile( String uri, Properties header, File homeDir,
                               boolean allowDirectoryListing )
    {
        Response res = null;

        // Make sure we won't die of an exception later
        if ( !homeDir.isDirectory())
            res = new Response( HTTP_INTERNALERROR, MIME_PLAINTEXT,
                "INTERNAL ERRROR: serveFile(): given homeDir is not a directory." );

        if ( res == null )
        {
            // Remove url arguments
            uri = uri.trim().replace( File.separatorChar, '/' );
            if ( uri.indexOf( '?' ) >= 0 )
                uri = uri.substring(0, uri.indexOf( '?' ));

            // Prohibit getting out of current directory
            if ( uri.startsWith( ".." ) || uri.endsWith( ".." ) || uri.indexOf( "../" ) >= 0 )
                res = new Response( HTTP_FORBIDDEN, MIME_PLAINTEXT,
                    "FORBIDDEN: Won't serve ../ for security reasons." );
        }

        File f = new File( homeDir, uri );
        if ( res == null && !f.exists())
            res = new Response( HTTP_NOTFOUND, MIME_PLAINTEXT,
                "Error 404, file not found." );

        // List the directory, if necessary
        if ( res == null && f.isDirectory())
        {
            // Browsers get confused without '/' after the
            // directory, send a redirect.
            if ( !uri.endsWith( "/" ))
            {
                uri += "/";
                res = new Response( HTTP_REDIRECT, MIME_HTML,
                    "<html><body>Redirected: <a href=\"" + uri + "\">" +
                    uri + "</a></body></html>");
                res.addHeader( "Location", uri );
            }

            if ( res == null )
            {
                // First try index.html and index.htm
                if ( new File( f, "index.html" ).exists())
                    f = new File( homeDir, uri + "/index.html" );
                else if ( new File( f, "index.htm" ).exists())
                    f = new File( homeDir, uri + "/index.htm" );
                // No index file, list the directory if it is readable
                else if ( allowDirectoryListing && f.canRead() )
                {
                    String[] files = f.list();
                    StringBuilder sb = new StringBuilder("<html><head><meta content=\"text/html; charset=UTF-8\" http-equiv=\"Content-Type\"></head><body><h1>Directory " + uri + "</h1><br/>");
                    // String msg = "<html><body><h1>Directory " + uri + "</h1><br/>";

                    if ( uri.length() > 1 )
                    {
                        String u = uri.substring( 0, uri.length()-1 );
                        int slash = u.lastIndexOf( '/' );
                        if ( slash >= 0 && slash  < u.length())
                            sb.append("<b><a href=\"" + uri.substring(0, slash+1) + "\">..</a></b><br/>");
                    }

                    if (files!=null)
                    {
                        for ( int i=0; i<files.length; ++i )
                        {
                            File curFile = new File( f, files[i] );
                            boolean dir = curFile.isDirectory();
                            if ( dir )
                            {
                                sb.append("<b>");
                                files[i] += "/";
                            }

                            sb.append("<a href=\"" + encodeUri( uri + files[i] ) + "\">" +
                                  files[i] + "</a>");

                            // Show file size
                            if ( curFile.isFile())
                            {
                                long len = curFile.length();
                                sb.append(" &nbsp;<font size=2>(");
                                if ( len < 1024 )
                                    sb.append(len + " bytes");
                                else if ( len < 1024 * 1024 )
                                    sb.append(len/1024 + "." + (len%1024/10%100) + " KB");
                                else
                                    sb.append(len/(1024*1024) + "." + len%(1024*1024)/10%100 + " MB");

                                sb.append(")</font>");
                            }
                            sb.append("<br/>");
                            if ( dir ) sb.append("</b>");
                        }
                    }
                    sb.append("</body></html>");
                    res = new Response( HTTP_OK, MIME_HTML, sb.toString());
                }
                else
                {
                    res = new Response( HTTP_FORBIDDEN, MIME_PLAINTEXT,
                        "FORBIDDEN: No directory listing." );
                }
            }
        }

        try
        {
            if ( res == null )
            {
                // Get MIME type from file name extension, if possible
                String mime = null;
                int dot = f.getCanonicalPath().lastIndexOf( '.' );
                if ( dot >= 0 )
                    mime = (String)theMimeTypes.get( f.getCanonicalPath().substring( dot + 1 ).toLowerCase());
                if ( mime == null )
                    mime = MIME_DEFAULT_BINARY;

                // Calculate etag
                String etag = Integer.toHexString((f.getAbsolutePath() + f.lastModified() + "" + f.length()).hashCode());

                // Support (simple) skipping:
                long startFrom = 0;
                long endAt = -1;
                String range = header.getProperty( "range" );
                if ( range != null )
                {
                    if ( range.startsWith( "bytes=" ))
                    {
                        range = range.substring( "bytes=".length());
                        int minus = range.indexOf( '-' );
                        try {
                            if ( minus > 0 )
                            {
                                startFrom = Long.parseLong( range.substring( 0, minus ));
                                endAt = Long.parseLong( range.substring( minus+1 ));
                            }
                        }
                        catch ( NumberFormatException nfe ) {}
                    }
                }

                // Change return code and add Content-Range header when skipping is requested
                long fileLen = f.length();
                if (range != null && startFrom >= 0)
                {
                    if ( startFrom >= fileLen)
                    {
                        res = new Response( HTTP_RANGE_NOT_SATISFIABLE, MIME_PLAINTEXT, "" );
                        res.addHeader( "Content-Range", "bytes 0-0/" + fileLen);
                        res.addHeader( "ETag", etag);
                    }
                    else
                    {
                        if ( endAt < 0 )
                            endAt = fileLen-1;
                        long newLen = endAt - startFrom + 1;
                        if ( newLen < 0 ) newLen = 0;

                        final long dataLen = newLen;
                        FileInputStream fis = new FileInputStream( f ) {
                            public int available() throws IOException { return (int)dataLen; }
                        };
                        fis.skip( startFrom );

                        res = new Response( HTTP_PARTIALCONTENT, mime, fis );
                        res.addHeader( "Content-Length", "" + dataLen);
                        res.addHeader( "Content-Range", "bytes " + startFrom + "-" + endAt + "/" + fileLen);
                        res.addHeader( "ETag", etag);
                    }
                }
                else
                {
                    if (etag.equals(header.getProperty("if-none-match")))
                        res = new Response( HTTP_NOTMODIFIED, mime, "");
                    else
                    {
                        res = new Response( HTTP_OK, mime, new FileInputStream( f ));
                        res.addHeader( "Content-Length", "" + fileLen);
                        res.addHeader( "ETag", etag);
                    }
                }
            }
        }
        catch( IOException ioe )
        {
            res = new Response( HTTP_FORBIDDEN, MIME_PLAINTEXT, "FORBIDDEN: Reading file failed." );
        }

        res.addHeader( "Accept-Ranges", "bytes"); // Announce that the file server accepts partial content requestes
        return res;
    }

    /**
     * Hashtable mapping (String)FILENAME_EXTENSION -> (String)MIME_TYPE
     */
    protected static Hashtable theMimeTypes = new Hashtable(); 
    static
    {
        StringTokenizer st = new StringTokenizer(
            "css        text/css "+
            "htm        text/html "+
            "html       text/html "+
            "xml        text/xml "+
            "txt        text/plain "+
            "json       application/json;charset=UTF-8 "+
            "asc        text/plain "+
            "gif        image/gif "+
            "jpg        image/jpeg "+
            "jpeg       image/jpeg "+
            "png        image/png "+
            "mp3        audio/mpeg "+
            "m3u        audio/mpeg-url " +
            "mp4        video/mp4 " +
            "ogv        video/ogg " +
            "flv        video/x-flv " +
            "mov        video/quicktime " +
            "swf        application/x-shockwave-flash " +
            "js         application/javascript "+
            "pdf        application/pdf "+
            "doc        application/msword "+
            "ogg        application/x-ogg "+
            "zip        application/octet-stream "+
            "exe        application/octet-stream "+
            "class      application/octet-stream " );
        while ( st.hasMoreTokens())
            theMimeTypes.put( st.nextToken(), st.nextToken());
    }

    private static int theBufferSize = 16 * 1024;

    private static String TAG = "web server:";
    private static Logger _logger = Logger.getLogger(SandroProxyWebService.class.getName());

    /**
     * GMT date formatter
     */
    private static java.text.SimpleDateFormat gmtFrmt;
    static
    {
        gmtFrmt = new java.text.SimpleDateFormat( "E, d MMM yyyy HH:mm:ss 'GMT'", Locale.US);
        gmtFrmt.setTimeZone(TimeZone.getTimeZone("GMT"));
    }

    /**
     * The distribution licence
     */
    private static final String LICENCE =
        "Copyright (C) 2001,2005-2011 by Jarno Elonen <elonen@iki.fi>\n"+
        "and Copyright (C) 2010 by Konstantinos Togias <info@ktogias.gr>\n"+
        "\n"+
        "Redistribution and use in source and binary forms, with or without\n"+
        "modification, are permitted provided that the following conditions\n"+
        "are met:\n"+
        "\n"+
        "Redistributions of source code must retain the above copyright notice,\n"+
        "this list of conditions and the following disclaimer. Redistributions in\n"+
        "binary form must reproduce the above copyright notice, this list of\n"+
        "conditions and the following disclaimer in the documentation and/or other\n"+
        "materials provided with the distribution. The name of the author may not\n"+
        "be used to endorse or promote products derived from this software without\n"+
        "specific prior written permission. \n"+
        " \n"+
        "THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR\n"+
        "IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES\n"+
        "OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.\n"+
        "IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,\n"+
        "INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT\n"+
        "NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,\n"+
        "DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY\n"+
        "THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT\n"+
        "(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE\n"+
        "OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.";
}
